Adrian Peterson ready to start running as ACL rehab progresses

This morning at the NFL owners meetings in West Palm Beach, Fla., Vikings head coach Leslie Frazier provided a brief update on the rehabilitation progress of injured running back Adrian Peterson.

The snapshot summary: Frazier said Peterson is "hitting his marks" and has in some ways "exceeded expectations" to this point as he tries to recover from the torn anterior cruciate ligament he suffered in his left knee during the Vikings' Christmas Eve win at Washington.

That said, Frazier is quick to point out that it's very early in the process and that Peterson will enter a critical stage this week. Peterson is back at Winter Park to begin running on ground for the first time under the watchful eye of Vikings head athletic trainer Eric Sugarman.

"We’ll get a better gauge of where he is once he starts running," Frazier said. "But everything he’s done up to this point has been very good. So we’re hoping once he starts running he’ll stay on course as well."

No one in the Vikings organization has backed off the idea that Peterson could be back in uniform and ready to go on Sept. 9 when the 2012 season opens. That would be 37 weeks from when Peterson suffered the injury.

"Ideally, we’d love to have him back opening day," Frazier said. "That’s what we’re aiming for. That’s what he wants to see happen. That’s what we’d all love to see happen. At the same time, we’ll have to be smart and see where he is. This is the beginning stages of his running. So we’ll have a better gauge in another one or two weeks as to what kind of progress he’s going to make. We need to determine, is he going to have any swelling after the first time he runs and then when he begins cutting and turning and twisting. It’s a long road ahead. But we’re hoping we’ll have him for the first game."

In the meantime, the Vikings plan to add backfield depth behind Peterson's understudy Toby Gerhart. After letting Lorenzo Booker walk during free agency, the Vikings will add another running back soon -- either via the draft or through free agency.